Cover photograph (Copyright © 2005, American Society for Microbiology. All Rights Reserved.): Electron micrograph of the Sulfolobus tengchongensis spindle-shaped virus STSV1. STSV1, which has the morphology of a large spindle (230 by 107 nm) with a tail of variable length (68 nm on average), infects the hyperthermophilic archaeon Sulfolobus tengchongensis from hot springs in southwestern China. The virus particles of STSV1 often occur singly but occasionally are clustered in a rosette-like pattern with tails attached to cell debris. Pseudocolors were assigned arbitrarily. (See related article on page 8677.)